Solenoid



, p 3', 1942- w. F. OLIVER 2,295,047

SOLENOID Filed Aug. 7, 1940 INVEI.VTOR MLZACEAOA/VAA BY c QJI MATTORNEYS Patented Sept. 8, 1942 UNITED STATES SOLENOID Wallace F.Oliver, South Bend, Ind., assignor to Bendix Home Appliances, Inc.,South Bend, Ind., a corporation of Delaware Application August 7, 1940,Serial No. 351,725 1 Claim. (01.175-241) This invention relates tosolenoids and more I particularly to solenoids having movable plungersadapted to operate a mechanism to be controlled.

One of the objects of the invention is to provide a solenoid which isextremely simple and inexpensive to produce but which is rugged andreliable. 1

Another object of the invention is to provide a solenoid in which theplunger is guided by relatively small surfaces spaced along itslength soas to reduce the friction drag. This construction enables the smallguiding surfaces to be accurately controlled so that thesolenoid will beguided properly in its movements with a minimum of friction. v

Another object of the invention is to provide a solenoid in whichcooperating parts on the plunger and the frame interengage to stopmovement of the plunger outwardly of the frame. According to oneimportant feature of the invention such interengaging parts serve notonly to stop the plunger, but also form the guiding surfaces for guidingthe plunger movement.

The above and other objects, advantages and novel features of theinvention will appear from the following description when read inconnection with the accompanying drawing, in which: a

Figure 1 is a perspective view of a solenoid em bodying the invention;

Figure 2 is a horizontal section through the solenoid and plunger ofFigure 1; I

Figure 3 is a partial view similar to Figure 2 with parts omitted;

. Figure 4 is a perspective view of a guide plate; and

Figure 5 is a perspective view of a stop plate.

The solenoid of Figure 1 comprises a O-shaped stack of laminations llforming a magnetic frame having an opening inone side thereof defined byopposed pole faces. The stack of laminations is held together by spacedrivets i2 and has secured to one side thereof a channel member I rivetedto one edge of the frame and forming a mounting means for the solenoid.It will be apparent of course, that various other types of mountingsmight be employed in lieu of the channel member ll.

A pair of guide plates ii are secured to the frame and extend from thesides of the opening therein to the portion of'the frame directlyonposite the opening. As best seen in Figure 4, the guide plates includeside portions terminating in a forward relatively narrow end I! and arearward end 20. The portion 20 is offset inwardly as seen in Figure 2so that the side portions of the guide plates will lie outside of theside planes of the frame. Intermediate the end portions the guide plateis formed with upper and lowerfianges 22 forming a guide channel.

The rearward end of the guide plate is secured to the frame in by a boltor the like 24 extending through the end portion "and through thelaminated frame. The forward end portion of the guide plate lies betweena pair of supporting plates 28 and 28 on one side of the frame andbetween a similar plate 28 and the forward end of a U-shaped bracket 30on the other side of the frame. The plates 28, as seen in Figure are ofsubstantially the same width as the laminations and are provided withspaced notches 32 to receive and support the forward edges of theflanges 22. Intermediate the ends of the plate 28 is an arcuatedepression 24 for a purpose to appear later. The plate 26 and theforward end of the bracket 30 are offset in their central portions tofit around the end portions ll of the guide plates, and the plates areall secured to the frame by bolts or rivets 36 extending through theframe adjacent the opening therein.

The bracket 3! bridges from the forward side of the frame adjacent theopening to the opposite side of the frame where its rearward end issecured by the bolt 2|. This bracket carries an insulating plate 38 uponwhich a pair of connector members 40 are mounted. A coil 42 lies withinthe magnetic frame ll around the guide plates l6 and has a pair ofterminals connected to the connectors ii.

A plunger indicated generally at U is slidable in the channel formed bythe guide plates I. through the opening in the frame il.- The plunger isformed of a stack of relatively thin laminations in the central portionthereof, two thicker laminatlons projecting beyond the end of theplunger at 46 and forming a connecting yoke. An operating lever 48extends between the plate portions I! and is pivotally connected theretoby a pin or the like.

As seen in Figure l the forward end of the plunger is provided withenlarged portions ll adapted substantially to close the opening in theframe when the plunger is in its innermost position. These enlargedportions are preferably of the form more particularly described andclaimed in my co-pending application, Serial No. 295,401 filed September18, 1939. In order to break the plunger loose from the effects ofresidual magnetism a spring plate 52 is secured to the forward endthereof and extends laterally from one side of the plunger to engage thefor- I ward end of the frame during the final inward movement of theplunger. The plate 52 has a pair of slots fitting over the portions 4'of the central laminations and is secured in place by a strip 54extending through slots in the portions 45.

The laminated plunger is secured together by a rivet or the like 56 atits forward end terminating substantially flush with the sides of theplunger. A similar rivet 58 at the rearward end of the plunger extendsthrough the stack of laminations and secures thereto a pair of washers50 projecting beyond th sides of the plunger.

When the parts are assembled the outer surfaces of the washers 60slidably engage the sides of the guide plates Hi to guide the rearwardend of the plunger. At the same time the plates 28 engage the sides ofthe plunger to guide the forward end thereof. It will be noted that theplates 28 lie in the path of movement of the projecting washers 60 andserve as stops to prevent the plunger from moving entirely out of themagnetic frame. Depressions such as 34 in the plates 28 may be providedto permit any desired degree of forward movement of the plunger beforeit is stopped by engagement of the washers 60 with the plates 28.

This construction provides a solenoid which is very simple andinexpensive to manufacture and in which the plunger is both properlyguided and stopped from moving outwardly of the frame to 5.11 undesiredextent.

While one particular construction has been described in detail it willbe understood that this is for the purposes of illustration only and isnot intended as a definition of the scope of the invention, referencebeing had for this purpose to the appended claim.

What is claimed is:

A solenoid comprising a C-shaped magnetic framehaving an opening at oneside for the reception of a plunger, a magnetic plunger slidable throughsaid opening, said plunger having lateral projections consisting ofrelatively large washers riveted to opposite sides of the plunger at itsrearward end extending beyond the sides of the plunger, guide means forthe plunger including guide plates carried by the frame and extendingfrom a point adjacent the opening to the opposite side of the frame,said guide plates including elongated side portions forming continuousbearing surfaces in engagement with the outer surfaces of saidprojections and intermediate top and bottom flanges overlying the topand bottom of the plunger, the rearward ends of the side portions beingoffset inwardly and lying against the sides of the frame and the forwardends of the side portions lying at the sides of said opening, and platesextending across said opening at the sides of the frame and lying withinthe forward ends of said side portions, said last named plates slidablyguiding the plunger and lying in the path of said projections to stopforward movement of the plunger.

WALLACE F. OLIVER.

